Police have opened a criminal investigation into the longtime football coach at Fort Wayne Bishop Luers High School after he was fired over inappropriate video clips found on his computer of students and other people, investigators said Thursday.

Allen County authorities began investigating after being contacted by the school on Tuesday, two days after it fired Matt Lindsay, whose 26-year career as head football coach included nine Indiana state titles. Lindsay also was the school's athletic director.

"This investigation is ongoing and no criminal activity on the part of Lindsay has been substantiated at this time," the Allen County Sheriff's Office said in a statement.

None of the videos contained nudity, but they were apparently surreptitiously recorded and have been turned over to investigators along with other evidence found by school officials, according to the Fort Wayne-South Bend Catholic Diocese.

Messages seeking comment were left Thursday on Lindsay's cellphone and at his home phone number.

The diocese, which oversees the school, declined to release any further description of the videos. The diocese said it learned of the videos on Lindsay's computer the evening of Sept. 12, and Luers Principal Mary Keefer placed him on administrative leave the next day. She fired Lindsay on Sunday.

"We do not know if the actions of Mr. Lindsay constitute a criminal offense. That is for the police to investigate and for law enforcement officials to evaluate," the diocese said in a statement.

But according to the school and diocese's judgment, the statement said, "the apparent surreptitious taking of video clips of students and other persons of the type taken by Mr. Lindsay constituted a violation of our ethical standards and policies, and thus mandated the immediate dismissal of Mr. Lindsay."

Bishop Kevin Rhoades said the diocese has "tried to proceed carefully and honestly, though under intense public pressure."

"My primary concern is the welfare of our students, the community of Bishop Luers High School, and the integrity of our actions. This whole affair has caused turmoil for many people. I ask for your prayers for the Bishop Luers community and for all involved in this very sad affair," Rhoades said in a statement.

The diocese's swift action in dismissing a highly successful football coach came three months after the conviction of former Penn State assistant football coach Jerry Sandusky on 45 counts of sexual abuse of boys and while a clergy sexual abuse scandal is still roiling the Roman Catholic Church.